You might have heard your teacher telling you to "simplify your final answers" when writing in fractional form.
It means to write an equivalent fraction with lowest possible denominator.
In general, a fraction is in its lowest terms when the greatest common factor (GCF) of the numerator and denominator is 1.
How to do it?
1. Find the greatest common factor of the numerator and denominator.
2. Divide both terms by their GCF.
3. The resulting fraction is in lowest terms.
Example 1:
$\frac{10}{18} $ = $\frac{10÷2}{18÷2} $= $\frac{5}{9}$
Recall that the GCF of 10 and 18 is 2. That is,
Factors of 10: 1, 2, 5, 10
Factors of 18: 1, 2, 3, 6, 9, 18
And so the lowest term of $\frac{10}{18} $ = $\frac{5}{9}$ since the GCF of both 5 and 9 is 1.
Example 2:
$\frac{15}{25} $ = $\frac{15÷5}{25÷5} $= $\frac{3}{5}$ since GCF of 15 and 25 is 5.
